Accuracy of MRI for treatment response assessment after taxane- and anthracycline-based neoadjuvant chemotherapy in HER2-negative breast cancer

Prediction of pathologic complete response on MRI in patients with breast cancer receiving neoadjuvant chemotherapy according to molecular subtypes

OBJECTIVES

This study aimed to investigate the predictability of breast MRI for pathologic complete response (pCR) by molecular subtype in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) and investigate the MRI findings that can mimic residual malignancy.

METHODS

A total of 506 patients with breast cancer who underwent MRI after NAC and underwent surgery between January and December 2018 were included. Two breast radiologists dichotomized the post-NAC MRI findings as radiologic complete response (rCR) and no-rCR. The diagnostic performance of MRI predicting pCR was evaluated. pCR was determined based on the final pathology reports. Tumors were divided according to hormone receptor (HR) and human epidermal growth factor receptor (HER) 2. Residual lesions on post-NAC MRI were divided into overt and subtle which classified as nodularity or delayed enhancement. Pearson's χ² and Wilcoxon rank-sum tests were used for MRI findings causing false-negative pCR.

RESULTS

The overall pCR rate was 30.04%. The overall accuracy for predicting pCR using MRI was 76.68%. The accuracy was significantly different by subtypes (p < 0.001), as follows in descending order: HR - /HER2 - (85.63%), HR + /HER2 - (82.84%), HR + /HER2 + (69.37%), and HR - /HER2 + (62.38%). MRI in the HR - /HER2 + type showed the highest false-negative rate (18.81%) for predicting pCR. The subtle residual enhancement observed only in the delayed phase was associated with false-negative findings (76.2%, p = 0.016).

CONCLUSIONS

The diagnostic accuracy of MRI for predicting pCR differed by molecular subtypes. When the residual enhancement on MRI after NAC is subtle and seen only in the delayed phase, overinterpretation of residual tumors should be performed with caution.

KEY POINTS

• In patients with breast cancer after completion of neoadjuvant chemotherapy, the diagnostic accuracy of MRI for predicting pathologic complete response (pCR) differed according to molecular subtype. • When residual enhancement on MRI is subtle and seen only in the delayed phase, this finding could be associated with false-negative pCR results.

Factors Associated With Surgical Modality Following Neoadjuvant Chemotherapy in Patients with Breast Cancer

BACKGROUND

The breast-conserving surgery (BCS) rate for patients with breast cancer in China is much lower than that in Europe and the United States. This study aimed to identify factors affecting the choice of surgical modality following neoadjuvant chemotherapy (NAC) in patients with breast cancer in northwest China.

PATIENTS AND METHODS

Patients who underwent mastectomy or BCS after NAC for invasive breast cancer from January 2013 to December 2017 were enrolled in the study. Single-factor and multivariate logistic regression analyses were applied to identify the association between the type of surgery and demographic characteristics or clinical pathological factors of patients.

RESULTS

This study enrolled 916 patients. Among them, 191 patients (20.9%) and 725 patients (79.1%) underwent BCS and mastectomy, respectively. Patients with high education were less likely to undergo mastectomy compared with patients with less education (P < .001; odds ratio [OR] = 0.50; 95% confidence interval [CI], 0.35-0.71). Patients with cT3 tumors were nearly six times more likely to undergo mastectomy compared with patients with cT1 tumors (P = .003; OR = 5.74; 95% CI, 2.07-15.97). Moreover, patients older than 50 years of age (P < .001; OR = 2.84; 95% CI, = 1.93-4.16) were more likely to be offered mastectomy. No association between the type of surgery and pathological complete response (P = .351) was observed.

CONCLUSION

Pretreatment clinical disease size remains a strong predictor of surgical management, whereas response to NAC appeared to play no role in the surgical decision, suggesting that the potential surgical benefits of NAC may be still under-recogonized in northwest China.

MRI Performance in Detecting pCR After Neoadjuvant Chemotherapy by Molecular Subtype of Breast Cancer

BACKGROUND

MRI performance in detecting pathologic complete response (pCR) post-neoadjuvant chemotherapy (NAC) in breast cancer has been previously explored. However, since tumor response varies by molecular subtype, it is plausible that imaging performance also varies. Therefore, we performed a literature review on subtype-specific MRI performance in detecting pCR post-NAC.

METHODS

Two reviewers searched Cochrane, PubMed, and EMBASE for articles published between 2013 and 2018 that examined MRI performance in detecting pCR post-NAC. After filtering, ten primary research articles were included. Statistical metrics, such as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were extracted per study for triple negative, HR+/HER2-, and HER2+ patients.

RESULTS

Ten studies involving 2310 patients were included. In triple negative breast cancer, MRI showed NPV (58-100%) and PPV (72.7-94.7%) across 446 patients and sensitivity (45.5-100%) and specificity (49-94.4%) in 375 patients. In HR+/HER2- breast cancer patients, MRI showed NPV (29.4-100%) and PPV (21.4-95.1%) across 851 patients and sensitivity (43-100%) and specificity (45-93%) across 780 patients. In HER2+-enriched subtype, MRI showed NPV (62-94.6%) and PPV (34.9-72%) in 243 patients and sensitivity (36.2-83%) and specificity (47-90%) in 255 patients.

CONCLUSION

MRI accuracy in detecting pCR post-NAC by subtype is not as consistent, nor as high, as individual studies suggest. Larger studies using standardized pCR definition with appropriate timing of surgery and MRI need to be conducted. This study has shown that MRI is in fact not an accurate prediction of pCR, and thus, clinicians may need to rely on other approaches such as biopsies of the tumor bed.

Evaluation of the response of breast cancer patients to neoadjuvant chemotherapy by combined contrast-enhanced ultrasonography and ultrasound elastography

The purpose of the present study was to investigate whether contrast-enhanced ultrasonography (CEUS) in combination with ultrasound elastography (UE) is able to accurately predict the efficacy of neoadjuvant chemotherapy (NAC) in breast cancer patients. A total of 65 breast cancer patients who received NAC at the First Affiliated Hospital of Zhejiang University (Hangzhou, China) between February 2016 and August 2017 and were recruited for the present study. Prior to and after NAC, examination by CEUS, UE or their combination was performed. Pathological results were obtained at the end of each chemotherapy cycle, based on which 41 cases were assigned to the response group and 24 to the non-response group. Kappa values were 0.710, 0.434 and 0.836 for CEUS, UE and CEUS+UE, respectively. The area under the receiver operating characteristic curves for CEUS, UE and CEUS+UE for determining the response to NAC was 0.864 [95% confidence interval (CI), 0.765–0.964], 0.715 (95% CI, 0.579–0.850) and 0.910 (95% CI, 0.826–0.993), respectively. It was identified that the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of CEUS+UE were higher than those of CEUS and US individually. The prediction accuracy was 89.2, 90.8 and 100% for CEUS, UE and their combination, respectively. CEUS and UE have their own advantages in evaluating the clinical efficacy of NAC in breast cancer, and a higher accuracy was achieved when the two techniques were applied in combination. Therefore, a combination of CEUS and UE may be a preferred method for the clinical assessment of the efficacy of NAC in breast cancer patients.

Phase II Study of S-1 Combined With Low-Dose Docetaxel as Neoadjuvant Chemotherapy for Operable Breast Cancer Patients (N-1 Study)

BACKGROUND

To improve the pathological complete response (pCR) rate, we devised new neoadjuvant chemotherapy. Efficacy and safety of the oral fluoropyrimidine derivative S-1 (Taiho Pharmaceutical Co, Tokyo, Japan) combined with low-dose docetaxel (S-1+DOC) were evaluated.

PATIENTS AND METHODS

Patients were treated with docetaxel (40 mg/m² intravenously on day 1) and S-1 (40 mg/m² orally twice per day on days 1-14) every 3 weeks for 4 cycles. In accord with the Response Evaluation Criteria In Solid Tumors version 1.1 criteria, the patients who showed a complete response (CR) underwent surgery, and those who achieved a partial response (PR) underwent 4 more cycles of S-1+DOC. Patients who achieved stable disease (SD) or progressive disease (PD) received EC (epirubicin and cyclophosphamide) or HT (trastuzumab and paclitaxel) according to their HER2 status. The primary end point was the pCR rate.

RESULTS

Ninety-four patients entered the study. After 4 cycles of S-1+DOC, CR was noted in 5 patients, PR in 57, SD in 18, and PD in 3. Of the patients who achieved SD and PD, 12 received EC, and 9 received HT. Among the 83 assessable patients, the pCR rate was 34.9%, and the response rate was 80.7%. The pCR rates were 19.5% in the luminal type group, 53.8% in the luminal HER2 group, 46.1% in the HER2 group, and 50.0% in the triple-negative group.

CONCLUSION

The S-1+DOC regimen in this study could be well tolerated and a new candidate neoadjuvant chemotherapy in operable breast cancer patients. It is also expected to be effective even in patients with luminal type disease. However, further randomized control trials are needed to ascertain whether pCR can contribute to favorable outcomes.

Human Epidermal Growth Factor 2-positive Breast Cancer with Mammographic Microcalcification: Relationship to Pathologic Complete Response after Neoadjuvant Chemotherapy

Purpose To determine the relationship between the presence or absence of mammographic calcifications in human epidermal growth factor receptor 2 (HER2)-positive breast cancers and pathologic complete response (pCR) to neoadjuvant chemotherapy and to determine other tumor and clinical characteristics that may be predictive of such a response. Materials and Methods A database of all patients with HER2-positive breast cancer who underwent neoadjuvant chemotherapy between 2007 and 2015 was retrospectively reviewed. Patient demographic characteristics, mammographic appearance, molecular subtype of cancer (luminal or nonluminal), radiologic response (based on breast magnetic resonance images), surgery, and pathologic response to treatment were recorded. Inter- and subgroup comparison was performed for presence of mammographic microcalcification and cancer subtype by using Mann-Whitney and χ2 tests and logistic regression. Results A total of 111 patients with a median age of 49 years (interquartile range, 40-57 years) were evaluated. Of these, 64.9% (72 of 111) had mammographic microcalcifications, 63.1% (70 of 111) had luminal B cancer, and 36.9% (41 of 111) had nonluminal HER2-positive cancer. Radiologic response to neoadjuvant chemotherapy was observed in 70.3% (78 of 111) of patients. Surgery was performed in 97.3% (108 of 111) of patients, and 30.6% (34 of 111) of patients underwent breast conservation. pCR was observed in 33.3% (37 of 111) of patients; 16.2% (18 of 111) showed residual ductal carcinoma in situ and 50.5% (56 of 111) had residual invasive disease. The pCR rate was the same (P = .21) in patients with mammographic microcalcification (29.2% [21 of 72]) as in those without calcification (41.0% [16 of 39]). The pCR rate in patients with nonluminal HER2-positive cancers (46.3% [19 of 41]) was higher (P = .01) than in those with luminal B cancers (25.7% [18 of 70]). pCR was associated with nonluminal HER2-positive subtype (odds ratio, 5.4; 95% confidence interval: 1.8, 16.0; P = .01) and complete radiologic response (odds ratio, 20.4; 95% confidence interval: 3.3, 126.6; P = .01). Conclusion Patients with HER2-positive cancer and mammographic microcalcification can achieve pCR after neoadjuvant chemotherapy. Nonluminal HER2-positive subtype and complete radiologic response are predictors of pCR.

Role of MR Imaging in Neoadjuvant Therapy Monitoring

Neoadjuvant chemotherapy (NAC) has become an important treatment approach for stage II/III breast cancers to downsize tumor and enable breast-conserving surgery for patients that may otherwise undergo mastectomy. MR imaging has the potential to identify early response or disease progression, enabling potential modification to NAC regimens. Detection of size and morphologic changes is better appreciated with MR imaging than other modalities and is different between molecular subtypes of breast cancer. The combination of DCE-MR imaging and DWI provides the highest sensitivity and specificity. Other new modalities such as FDG PET/MR imaging and molecular breast imaging are still undergoing research.

Combining multiparametric MRI with receptor information to optimize prediction of pathologic response to neoadjuvant therapy in breast cancer: preliminary results

Pathologic complete response following neoadjuvant therapy (NAT) is used as a short-term surrogate marker of eventual outcome in patients with breast cancer. Analyzing voxel-level heterogeneity in MRI-derived parametric maps, obtained before and after the first cycle of NAT ([Formula: see text]), in conjunction with receptor status, may improve the predictive accuracy of tumor response to NAT. Toward that end, we incorporated two MRI-derived parameters, the apparent diffusion coefficient and efflux rate constant, with receptor status in a logistic ridge-regression model. The area under the curve (AUC) and Brier score of the model computed via 10-fold cross validation were 0.94 (95% CI: 0.85, 0.99) and 0.11 (95% CI: 0.06, 0.16), respectively. These two statistics strongly support the hypothesis that our proposed model outperforms the other models that we investigated (namely, models without either receptor information or voxel-level information). The contribution of the receptor information was manifested by an 8% to 15% increase in AUC and a 14% to 21% decrease in Brier score. These data indicate that combining multiparametric MRI with hormone receptor status has a high likelihood of improved prediction of pathologic response to NAT in breast cancer.

Thermal tomography for monitoring tumor response to neoadjuvant chemotherapy in women with locally advanced breast cancer

BACKGROUND & AIMS

This study aims to analyze the feasibility and predictive value of thermal tomography (TT) for monitoring early treatment response in patients with locally advanced breast cancer (LABC) receiving neoadjuvant chemotherapy (NAC).

METHODS

Patients with LABC who were due to receive six cycles of NAC were examined by TT prior to NAC, the second cycle of NAC, the fourth cycle of NAC and surgery. Changes in TT parameters and ultrasonography were correlated with pathologic response to NAC, and the predictive value was assessed.

RESULTS

Forty-four patients were evaluable for response (25 pathologic responders and 19 nonresponders). As early as after the first cycle of NAC, changes in the TT parameters ΔTs, ΔTn, and ΔTa correlated significantly with pathologic response (P < 0.05). The best predictor of pathologic response after the 6th cycle of NAC was TT (area under the receiver operating characteristic curve, 0.794), as opposed to cross-sectional areas and the longest diameter by ultrasonography.

CONCLUSIONS

TT allows for monitoring early tumor response to NAC and can predict pathologic response in the early stages of therapy. Therefore, TT could be used as a novel imaging modality to monitor NAC treatment.

Association Between Background Parenchymal Enhancement and Pathologic Complete Remission Throughout the Neoadjuvant Chemotherapy in Breast Cancer Patients

PURPOSE

To retrospectively investigate the quantitative background parenchymal enhancement (BPE) of the contralateral normal breast in patients with unilateral invasive breast cancer throughout multiple monitoring points of neoadjuvant chemotherapy (NAC) and to further determine whether BPE is associated with tumor response, especially at the early stage of NAC.

MATERIALS AND METHODS

A total of 90 patients with unilateral breast cancer who then received six or eight cycles of NAC before surgery were analyzed retrospectively. BPE was measured in dynamic contrast-enhanced MRI at baseline and after 2nd, 4th, and 6th NAC, respectively. Correlation between BPE and tumor size was analyzed, and the association between pathologic complete remission (pCR) and BPE was also analyzed.

RESULTS

The BPE of contralateral normal breast showed a constant reduction throughout NAC therapy regardless of the menopausal status (P<.001 in all). Both the BPEs and the changes of BPE in each of the three monitoring points were significantly correlated with those in tumor size (P<.05 in all), and the reduction of BPE after 2nd NAC had the largest diagnostic value for pCR (AUC=0.726, P<.001), particularly in hormonal receptor (HR)-negative patients (OR=0.243, 95%CI=0.083 to 0.706, P=.009).

CONCLUSION

The BPE of contralateral normal breast had a constant decreased tendency similar to the change of tumor size in NAC. Reduction of BPE at the early stage of NAC was positively associated with pCR, especially in HR-negative status.

Breast magnetic resonance imaging use in patients undergoing neoadjuvant chemotherapy is associated with less mastectomies in large ductal cancers but not in lobular cancers

BACKGROUND

To assess the impact of breast magnetic resonance imaging (MRI) use on surgical outcome per histological breast cancer subtype in patients treated with neoadjuvant chemotherapy.

PATIENTS AND METHODS

All patients aged 18-70 years who underwent neoadjuvant chemotherapy for stage I-III invasive breast cancer in the Netherlands in the years 2011-2013 were identified from the Netherlands Cancer Registry. Patients with cT4 tumours were excluded from the analysis. Use of breast MRI and impact on surgical treatment, resection margins and detection of contralateral breast cancer were analysed by multivariable analyses.

RESULTS

Breast MRI was performed in 2879 (83.9%) out of 3433 patients treated with neoadjuvant chemotherapy. Younger age (odds ratio [OR] 1.42; 95% confidence interval [CI] 1.17-1.71 for 18-50 years compared with 50-70 years), larger tumour stage (OR 1.46 [95% CI 1.15-1.86] for cT3, compared to cT1-2 tumours) and multifocality (OR 1.30; 95% CI 1.04-1.61, versus unifocality) were associated with increased breast MRI use. In ductal breast cancer, after stratification for cT-status, breast MRI use is associated with a significant lower OR for mastectomy as final surgery in cT3 tumours (OR 0.45, 95% CI 0.21-0.99). Resection margin involvement and detection of contralateral breast cancer were not associated with breast MRI use.

CONCLUSION

In patients treated with neoadjuvant chemotherapy, the use of breast MRI was associated with a reduced mastectomy rate, particularly in patients with large invasive ductal breast tumours but not in patients with lobular breast cancer.

Tumor burden monitoring using cell-free tumor DNA could be limited by tumor heterogeneity in advanced breast cancer and should be evaluated together with radiographic imaging

Background

Accurate measurement of tumor burden in breast cancer disease is essential to improve the clinical management of patients. In this study, we evaluate whether the fluctuations in the fraction of PIK3CA mutant allele correlates with tumor response according to RECIST criteria and tumor markers quantification.

Methods

Eighty six plasma samples were analyzed by digital PCR using Rare Mutation Assays for E542K, E545K and H1047R. Mutant cfDNA and tumor markers CA15-3 and CEA were compared with radiographic imaging.

Results

The agreement between PIK3CA mutation status in FFPE samples and circulating tumor DNA (ctDNA) was moderate (K = 0.591; 95% IC = 0.371–0.811). Restricting the analysis to the metastatic patients, we found a good agreement between PIK3CA mutation status assessed in liquid and solid biopsy (K = 0.798 95%; IC = 0.586–1). ctDNA showed serial changes with fluctuations correlating with tumor markers 15.3 and CEA in 7 out of 8 cases with Pearson correlation coefficients ranging from 0.99 to 0.46 and from 0.99 to 0.38 respectively. Similarly, fluctuations in the fraction of PIK3CA mutant allele always correlated with changes in lesion size seen on images, although in two cases it did not correlate with treatment responses as defined by RECIST criteria.

Conclusion

oncogenic mutation quantification in plasma samples can be useful to monitor treatment outcome. However, it might be limited by tumor heterogeneity in advanced disease and it should be evaluated together with radiographic imaging.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3185-9) contains supplementary material, which is available to authorized users.

Specific adverse events are associated with response to exemestane therapy in postmenopausal breast cancer patients: Results from the TEAMIIA study (BOOG2006-04)

PURPOSE

In the adjuvant setting, specific adverse events (AEs) such as vasomotor symptoms (VMS) and musculoskeletal AEs are associated with relapse-free survival in aromatase inhibitor (AI)-treated patients. In the neoadjuvant setting, specific AEs may be associated with tumor response to AIs as well.

METHODS

Between 2007 and 2012, 107 patients participated in the prospective TEAMIIA trial, a prospective, phase II trial investigating 6 months of neoadjuvant exemestane in patients with strongly ER-positive breast cancer. Radiological response (≥30% decrease in tumor size) was studied in relation to VMSs and MSAEs. Pearson's Chi-Square tests and multivariate logistic regression analyses were used to evaluate of statistical significance (p < 0.05).

RESULTS

Out of 102 patients 26 patients (25.4%) experienced at least one episode of VMS and 27 patients (26.4%) experienced MSAE. Out of 240 reported adverse events, 71 were specific AEs (40 MSAEs, 31 VMSs). Radiological response was greater in patients who reported VMSs compared to patients who did not (70.8% vs. 49.3%, multivariate OR 2.91, 95% C.I. 1.03-8.26, P = 0.045). No significant advantage towards better response was observed in patients who experienced MSAEs (60.0% vs. 53.3%, univariate OR 1.33, 95% C.I. 0.53-3.38, P = 0.545).

CONCLUSION

VMSs are associated with tumor response to neoadjuvant exemestane and may be useful for predicting treatment outcomes of AI treatment at an early stage in patients treated with neoadjuvant AIs.

Reliability of MRI in measuring the response to neoadjuvant chemotherapy in breast cancer patients and its therapeutic implications

Aim: Neoadjuvant chemotherapy (NAC) has recently been applied in treatment of operable breast cancers to enable breast conservation. We aimed to evaluate the accuracy of MRI in delineating residual tumor and pathological complete response (pCR). Patients & methods: 69 cases treated with NAC were monitored using breast MRI, findings were recorded and compared with histopathology. Results: MRI showed radiological complete response in 19 (27.5%), which correlated with pCR in 12 (63%) cases. However, five (7.3%) patients who achieved pCR were missed. Overall, the sensitivity was 70.6%, specificity 86.5%, positive predictive value 63.2% and negative predictive value of 90.0%. Conclusion: MRI showed promising results for evaluating response to NAC and predicting pCR, results need validation in larger trial.

Assessment of Residual Disease With Molecular Breast Imaging in Patients Undergoing Neoadjuvant Therapy: Association With Molecular Subtypes

BACKGROUND

Assessment of residual disease after neoadjuvant therapy for breast cancer is an ongoing challenge of breast imaging. This study evaluates the accuracy of a novel dedicated system for molecular breast imaging (MBI) composed of the new generation of cadmium zinc telluride detectors in assessing residual disease after neoadjuvant therapy in patients with breast cancer.

PATIENTS AND METHODS

Clinical data, imaging, surgical, and pathological findings of 51 women with breast cancer undergoing neoadjuvant therapy were recorded. MBI findings were correlated with surgical pathology results. Accuracy of MBI in predicting complete pathological response and size of residual disease was assessed according to molecular subtypes.

RESULTS

The size of the largest focus of uptake on MBI correlated with the largest dimension measured on pathology (r = 0.55; P < .001). This correlation was stronger for triple negative and HER2/neu positive subtypes (r = 0.92 and 0.62, respectively). Sixteen patients (31%) had complete pathological response. The sensitivity and specificity of MBI for detecting residual disease were 83% (95% confidence interval [CI], 66-93) and 69% (95% CI, 42-88), respectively. For triple negative or HER2/neu positive disease the sensitivity and specificity were 88% (95% CI, 62-98) and 75% (95% CI, 43-93), respectively.

CONCLUSION

The accuracy of MBI in assessing residual disease after neoadjuvant treatment might be related to the molecular subtype. Accuracy is highest in the triple negative and HER2/neu positive subtypes.

Cardiotoxicity of anthracycline therapy: current perspectives

Anthracyclines, especially doxorubicin and daunorubicin, are the drugs of first choice in the treatment of patients with hematologic malignancies, soft-tissue sarcomas, and solid tumors. Unfortunately, the use of anthracyclines is limited by their dose-dependent and cumulative cardiotoxicity. The molecular mechanism responsible for anthracycline-induced cardiotoxicity remains poorly understood, although experimental and clinical studies have shown that oxidative stress plays the main role. Hence, antioxidant agents, especially dexrazoxane, and also other drug classes (statins, β-blockers) proved to have a beneficial effect in protecting against anthracycline-induced cardiotoxicity. According to previous clinical trials, the major high-risk factors for anthracycline-induced cardiotoxicity are age, body weight, female gender, radiotherapy, and other diseases such as Down syndrome, familial dilated cardiomyopathy, diabetes and hypertension. Consequently, further studies are needed to elucidate the molecular pathogenesis of anthracycline-induced cardiotoxicity and also to discover new cardioprotective agents against anthracycline-induced cardiotoxicity.

Ultrasound is at least as good as magnetic resonance imaging in predicting tumour size post-neoadjuvant chemotherapy in breast cancer

BACKGROUND

The aim of this study was to evaluate the accuracy of clinical imaging of the primary breast tumour post-neoadjuvant chemotherapy (NAC) related to the post-neoadjuvant histological tumour size (gold standard) and whether this varies with breast cancer subtype. In this study, results of both magnetic resonance imaging (MRI) and ultrasound (US) were reported.

METHODS

Patients with invasive breast cancer were enrolled in the INTENS study between 2006 and 2009. We included 182 patients, of whom data were available for post-NAC MRI (n=155), US (n=123), and histopathological tumour size.

RESULTS

MRI estimated residual tumour size with <10-mm discordance in 54% of patients, overestimated size in 28% and underestimated size in 18% of patients. With US, this was 63%, 20% and 17%, respectively. The negative predictive value in hormone receptor-positive tumours for both MRI and US was low, 26% and 33%, respectively. The median deviation in clinical tumour size as percentage of pathological tumour was 63% (P25=26, P75=100) and 49% (P25=22, P75=100) for MRI and US, respectively (P=0.06).

CONCLUSIONS

In this study, US was at least as good as breast MRI in providing information on residual tumour size post-neoadjuvant chemotherapy. However, both modalities suffered from a substantial percentage of over- and underestimation of tumour size and in addition both showed a low negative predictive value of pathologic complete remission (Gov nr: NCT00314977).

Do MRI and mammography reliably identify candidates for breast conservation after neoadjuvant chemotherapy?

BACKGROUND

Neoadjuvant chemotherapy (NAC) may allow breast-conserving therapy (BCT) in patients who require mastectomy at presentation. Breast MRI is more accurate than mammography in assessing treatment response, but combined test reliability in identifying BCT candidates after NAC is not well described. We evaluated whether post-NAC breast MRI alone and with mammography accurately identifies BCT candidates.

METHODS

In this retrospective study of 111 consecutive breast cancer patients receiving NAC, all had pre- and postchemotherapy MRI, followed by surgery. Posttreatment MRI and mammography results were correlated with surgical outcomes and pathologic response.

RESULTS

Fifty-one of 111 (46 %) patients presented with multicentric or inflammatory breast cancer and were not BCT candidates. The remaining 60 (54 %) were considered BCT candidates after downstaging (mean age: 47 years). All 60 had at least a partial response to NAC and were suitable for BCT on MRI after NAC. Forty-five of 60 (75 %) underwent lumpectomy; 15 of 60 (25 %) chose mastectomy. Forty-one of 45 (91 %) of lumpectomies were successful; 4 of 45 (9 %) required mastectomy. Twelve of 15 (80 %) patients choosing mastectomy could have undergone BCT based on pathology; 3 of 15 (20 %) did require mastectomy. Two of these three patients had extensive microcalcifications on mammogram, indicating the need for mastectomy despite MRI suitability for BCS. MRI alone correctly predicted BCS in 53 of 60 (88 %) patients. MRI plus mammography was correct in 55 of 60 (92 %), although only 9 of 45 (20 %) BCT patients and 4 of 15 (27 %) potentially conservable mastectomy patients had complete pathologic responses.

CONCLUSIONS

Posttreatment MRI plus mammography is an accurate method to determine whether BCT is possible after NAC is given to downstage disease.

Optical mammography using diffuse optical spectroscopy for monitoring tumor response to neoadjuvant chemotherapy in women with locally advanced breast cancer

PURPOSE

Diffuse optical spectroscopy (DOS) has the potential to enable monitoring of tumor response during chemotherapy, particularly in the early stages of treatment. This study aims to assess feasibility of DOS for monitoring treatment response in HER2-negative breast cancer patients receiving neoadjuvant chemotherapy (NAC) and compare DOS with tumor response assessment by MRI.

EXPERIMENTAL DESIGN

Patients received NAC in six cycles of 3 weeks. In addition to standard treatment monitoring by dynamic contrast enhanced MRI (DCE-MRI), DOS scans were acquired after the first, third, and last cycle of chemotherapy. The primary goal was to assess feasibility of DOS for early assessment of tumor response. The predictive value of DOS and DCE-MRI compared with pathologic response was assessed.

RESULTS

Of the 22 patients, 18 patients had a partial or complete tumor response at pathologic examination, whereas 4 patients were nonresponders. As early as after the first chemotherapy cycle, a significant difference between responders and nonresponders was found using DOS (HbO2 86% ± 25 vs. 136% ± 25, P = 0.023). The differences between responders and nonresponders continued during treatment (halfway treatment, HbO2 68% ± 22 vs. 110% ± 10, P = 0.010). Using DCE-MRI, a difference between responders and nonresponders was found halfway treatment (P = 0.005) using tumor volume measurement calculations.

CONCLUSIONS

DOS allows for tumor response assessment and is able to differentiate between responders and nonresponders after the first chemotherapy cycle and halfway treatment. In this study, DOS was equally effective in predicting tumor response halfway treatment compared with DCE-MRI. Therefore, DOS may be used as a novel imaging modality for (early) treatment monitoring of NAC.